Upgrades the look and feel of Yahoo! E-mail. The message header for an e-mail, if you use the preview pane, is now fixed so you can scroll through the message and not miss who wrote the message. Few other enhancements to make Yahoo components easier to find.

You should only use this style if you use the preview pane. If you don't know how to activate the preview pane go to "Options" => "Mail Options" => "Messages:" => "Show all messages in a scrolling list (with Preview Pane option)" => "Save Changes"